Change-over unit for hoisting appliances

ABSTRACT

A change-over unit for hoisting appliances with a lower block suspended in a plurality of rope parts from an upper block, and with an intermediate block inserted between said blocks, the intermediate block being adapted to be arbitrarily coupled to the upper block or to the lower block to change the transmission ratio and the permissible load, the upper block (1) being provided with at least one releasable coupling member (11) which is arranged to engage at least one coupling member (15) provided on the intermediate block (8), the lower block (5) having at least one uncoupling member (16) which is designed as a releasing member for the coupling member (11) of the upper block (1), said coupling member being adapted to be arbitrarily placed in a releasing position or a neutral position.

United States Patent 1 Kroll et a1.

1451 Feb. 26, 1974 1 CHANGE-OVER UNIT FOR HOISTING APPLIANCES [22]Filed: Aug. 23, 1971 [21] Appl. N0.: 173,781

[30] Foreign Application Priority Data Apr. 5, 1971 Germany.., 2116544[52] US. Cl. 212/105, 212/27 [51] Int. Cl. B66c 21/00 [58] Field ofSearch 212/27, 24, 102-105, 212/123; 188/1 B, 129

[56] References Cited UNITED STATES PATENTS 3,306,469 2/1967 Durand .L212/102 X FOREIGN PATENTS OR APPLICATIONS 171,531 7/1965 U.S.S.R 212/10256,734 8/1912 Austria 212/104 1,201,189 9/1965 Germany 188/129 PrimaryExaminer-Richard E. Aegerter Assistant Examiner-Bruce l-l. Stoner, Jr.Attorney, Agent, or Firm-Brumbaugh, Graves, Donohue & Raymond [57]ABSTRACT A change-over unit for hoisting appliances with a lower blocksuspended in a plurality of rope parts from an upper block, and with anintermediate block inserted between said blocks, the intermediate blockbeing adapted to be arbitrarily coupled to the upper block or to thelower block to change the transmission ratio and the permissible load,the upper block (1) being provided with at least one releasable couplingmember (11) which is arranged to engage at least one coupling member(15) provided on the intermediate block (8), the lower block (5) havingat least one uncoupling member (16) which is designed as a releasingmember for the coupling member (11) of the upper block (1), saidcoupling member being adapted to be arbitrarily placed in a releasingposition or a neutral position.

5 Claims, 6 Drawing Figures 01/581. 040 COL PL l/VG PMENTED FEBZ 6 I974saw 3 OF 6 PMENTED FEB 2 6 I974 SHEET 0F 6 PATENTEBFEBZBISM SHEET 6 [IF6 CHANGE-OVER UNIT FOR HOISTING APPLIANCES The present invention relatesto a change-over unit for hoisting appliances with a lower blocksuspended in a plurality of rope parts from an upper block, and with anintermediate block inserted between said blocks, and wherein theintermediate block can be arbitrarily coupled to the upper block or tothe lower block to change the transmission ratio and the permissibleload.

Depending upon the coupling of the intermediate block to the lower blockor to the upper block .the hoisting appliance may, e.g., operatewithtwo, respectively four parts of rope.

The invention has for its object .toprovide a unitby means of which thechange-over operation canlbe executed simply and semi-automatically.

According to the invention this object is substantially attained byproviding the upper block with at least one releasable coupling memberwhich is arranged to engage at least one coupling member provided on theintermediate block, and by providing the lower block with at least oneun-coupling member which is designed as a releasing member for thecoupling member of the upper block, and which can be arbitrarily placedin a releasing position or a neutral position.

If by means of the lower block the intermediate block is hoisted intocontact with the upper block,and the releasing member is in its neutralposition, the intermediate block will be coupled to the upper block. Inthis manner a change-over can be made from operation, c.g., with twoparts of rope to operation with four parts of rope, as the intermediateblock remains coupled to the upper block when the lower block islowered. If it is wanted again to change over from operation with fourparts to operation with two parts of rope, the releasing member placedon the lower block is moved to releasing position, which can easily bedone from the ground when the lower block has been lowered. When,thereupon, the lower block is hoisted, the releasing member will releasethe coupling connection between the upper block and the intermediateblock, and the intermediate block can now be lowered together with thelower block, which is tantamount to a resumption of operation with twoparts of rope. The two-parts operation continues for as long as thereleasing member remains in its releasing position. Not until thereleasing member is returned to its neutral position can theintermediate block be coupled to the upper block again, and achange-over to four-parts operation can take place. Four-parts operationcontinues for as long as the releasing member is allowed to remain inits neutral position.

According to the invention the coupling members may be designed asclutches and the releasing member as a filling member which may enterthe gap of the clutch in the coupling member of the intermediate block.In a particularly simple but robust construction of this embodiment thefilling member may, according to the invention, consist of a slidingpawl which is swingably mounted on the lower block.

Furthermore, in an appropriate embodiment of the invention the couplingclutch of the upper block may be formed as a swingable, springloadedcoupling member and the coupling clutch of the intermediate block as astationary coupling member opposite the clutch of the upper block,whereby a simple and reliable construction is obtained.

In still another embodiment of the change-over unit according to theinvention the lower block and/or the upper block may be provided with atleast one resiliently yielding stop member facing the upper block,respectively the lower block, which said stop member is adapted to abutagainst the counter block, and the stop member may be so designed andpositioned as to abut against the counter block, before the couplingmembers of the two blocks engage one another. This implies that thecoupling connection is not effected until a certain elastic resistanceof the stop member has been overcome. The thrust resulting from thisserves to secure the coupling connection now established.

In a particularly suitable embodiment of the latter example of theinvention the hoisting appliance according to the invention may beprovided with an overload coupling, which is adapted to come intooperation after the coupling together of the coupling members.Consequently, a special switch disconnecting the hoisting applianceafter the coupling of the intermediate block to the upper block will besuperfluous.

In the following the invention will be described in more detail,reference being had to the drawing which shows a particularlyappropriate embodiment of the change-over unit according to theinvention.

FIG. 1 showing the unit arranged for operation with two parts of rope,

FIG. 2 the unit prepared for changing over to operation with four partsof rope,

FIG. 3the unit immediately before changing over to operation with fourparts of rope,

FIG. 4 the unit arranged for operation with four parts of rope,

FIG. 5 the unit prepared for changing over to operation with two partsof rope, and

FIG. 6 shows a further embodiment of the unit.

The drawing shows a travelling trolley 1, which by means of travellingrollers 2 is movably suspended from a travel-rail 3. The trolley isprovided with two rope pulleys 4 and constitutes the upper block in ahoisting appliance.

A lower block 5 provided with rope pulleys 6 and a crane hook 7 issuspended from said lower block.

The hoisting appliance furthermore comprises an intermediate block 8with a rope pulley 9.

The rope 10 of the hoisting appliance has been passed over the ropepulleys 4 and 9 and under the rope pulleys 6.

Furthermore, the travelling trolley or upperblock 1 has two couplingclutches 11, the coupling gaps of which facing one another. Bothclutches are swingable about separate axes l2 and are urged in directiontowards each other, each by its own compression spring 13, theirmovement of swinging in said direction being restricted by stop members14.

The intermediate block 8 is provided with similarly designed andpositioned counter clutches 15, which are in fixed connection with theblock and whose gaps face away from one another.

The lower block 5 is provided with swingably mounted sliding pawls 16which are designed and positioned in such a way that they may be swunginto and at least partially fill out the gaps in the clutches 15 of theintermediate block 8, when the intermediate block 8 is coupled to thelower block 5.

Moreover, the lower block 5 is provided with resiliently yielding stopmembers 17 in the form of caoutchouc buffers, which extend freely someway up from the side of the lower block 5 facing the upper block 1 andare located on opposite sides of the intermediate block 8. As shown inFIG. 6, the resiliently yielding stop member 17 may also be attached tothe upper block 1 and face the lower block 5.

The change-over unit described heretofore operates as follows:

Assume that the unit is in the position shown in FIG. 1. In thisposition the intermediate block 8 is coupled to the lower block 5 byresting on a supporting surface 18 of the lower block, whereby theintermediate block 8 is held in this abutting position by means of therope arrangement described in the foregoing. The sliding pawls 16 havebeen swung into their releasing position in the gaps of the clutches 15.The lower block 5 is suspended in two rope parts 10a and 10b togetherwith the intermediate block 8.

In this condition the unit is arranged for operation with two parts ofrope, the sliding pawls 16, having been turned inwardly, preventing theclutches 11 of the upper block 1 from engaging the clutches 15 of theintermediate block 8, in case of lower block 5 is hoisted all the way uptogether with the intermediate block 8.

If it is desired to change over to operation with four parts of rope,the sliding pawls 16 are swung out into neutral position as shown inFIG. 2, which can be easily done from the ground, when the lower block 5has been hauled down. This means that the clutches 15 of theintermediate block 8 have now been opened for engaging the clutches llof the upper block 1.

The first thing which happens if, now, by means of the lower block 5 theintermediate block 8 is hoisted towards the upper block 1, is that thecaoutchouc buffers 17 or 17' come into abutment with the upper block 1.Continued raising of the lower block 5 will effect a compression of thebuffers 17 or 17, whereby partly the position of the lower block 5 andconsequently also the position of the intermediate block 8 in relationto the upper block 1 are secured, and partly a thrust is accumulated inthe buffers. After a certain compression of the buffers 17 or 17 theclutches 11 and 15 will engage each other, as initially the clutches 15against the spring load of the clutches II will force the latterslightly backwards, and thereupon the clutches 11 urged by thecompression springs 13 will engage the clutches 15.

Furthermore, the hoisting appliance is provided with an overloadcoupling 18, shown in FIG. 1, which now starts functioning, i.e., afterthe clutches 11 and 15 have engaged one another. This means that thethrust accumulated in the buffers 17 or 17 now also contributes tosecure the engagement of the clutches.

Hereafter the unit operates with four parts of rope, as the intermediateblock 8 is now coupled to the upper block 1, and thus the lower block issuspended in four rope parts, 10a, 10b, 10c, and 10d, see FIG. 4.

Operation with four parts of rope continues for as long as the slidingpawls 16 remain in the neutral position shown in FIGS. 2-4. Not untilthey are again swung into their releasing position, as shown in FIG. 5,which also can be done without difficulty from the ground if the lowerblock 5 has been hauled down, is a changeover to operation with twoparts of rope prepared again, as the pawls 16 may then, when the lowerblock S is hoisted all the way up, penetrate between the clutches 11 and15 and force the clutches 11 to disengage the clutches 15. As long asthe pawls 15 are allowed to remain in their releasing position, the unitis again arranged for operation with two parts of rope, as described inconnection with FIG. 1.

The unit herein described can also be applied in a modified form tochange-over operations with other numbers of rope parts withoutdeparting from the principle of the invention as explained in theforegoing.

What we claim is:

l. A change-over unit for hoisting appliances comprising:

an upper block having at least one releasable coupling member and aplurality of rope parts;

a lower block for connection to a load to be hoisted, the lower blockbeing suspended from and hoisted toward the upper block by the ropeparts and including means for releasing the coupling member of the upperblock, said means including at least one releasing member having aneutral position and a releasing position;

an intermediate block inserted between the upper and lower blocks andsupported by the lower block, the intermediate block having at least onecoupling member arranged to engage the releasable coupling member on theupper block when the lower and intermediate blocks are hoisted towardthe upper block, the intermediate block (1) being coupled to the upperblock, when said releasing member is in the neutral position, to suspendthe intermediate block from the upper block and (2) being supported bythe lower block when said releasing member is in the releasing position,the intermediate block further including means for increasing the numberof rope parts when the intermediate block is suspended from the upperblock to change the transmission ratio and the permissible load of thehoisting appliance when the coupling members are engaged and theintermediate block is suspended from the upper block; and

at least one resiliently yielding stop member supported by the lowerblock in facing relation to the upper block, the stop member abuttingagainst the upper block before the coupling members of the intermediateand upper blocks engage one another to compress said stop member, saidcompressed stop member securing the lower block with respect to theupper block and, upon engagement of the coupling members, exerting athrust tending to secure such engagement.

2. A change-over unit according to claim 1, characterized in that thehoisting appliance is provided with an overload coupling, which isadapted to come into operation after the coupling together of thecoupling members.

3. A change-over unit according to claim 2, wherein the overloadcoupling comes into operation upon continued hoisting of theintermediate and lower blocks after the coupling together of thecoupling members.

4. A change-over unit according to claim 1, wherein the stop member hasareas for abutment with the upper block that are positioned instraddling relation with the intermediate block.

5. A change-over unit for hoisting appliances comprising:

an upper block having at least onereleasable coupling member and aplurality of rope parts;

a lower block for connection to a load to be hoisted,

the lower block being suspended from and hoisted toward the upper blockby the rope parts and including means for releasing the coupling memberof the upper block, said means including at least one releasing memberhaving a neutral position and a releasing position;

an intermediate block inserted between the upper releasing position, theintermediate block further including means for increasing the number ofrope parts when the intermediate block is suspended from the upper blockto change the transmission ratio and the permissible load of thehoisting appliance when the coupling members are engaged and theintermediate block is suspended from the upper block; and

at least one resiliently yielding stop member supported by the upperblock in facing relation ,to the lower block, the stop member abuttingagainst the lower block before the coupling members of the intermediateand upper blocks engage one another to compress said stop member, saidcompressed stop member securing the lower block with respect to theupper block and, upon engagement of the coupling members, exerting athrust tending to secure such engagement.

1. A change-over unit for hoisting appliances comprising: an upper blockhaving at least one releasable coupling member and a plurality of ropeparts; a lower block for connection to a load to be hoisted, the lowerblock being suspended from and hoisted toward the upper block by therope parts and including means for releasing the coupling member of theupper block, said means including at least one releasing member having aneutral position and a releasing position; an intermediate blockinserted between the upper and lower blocks and supported by the lowerblock, the intermediate block having at least one coupling memberarranged to engage the releasable coupling member on the upper blockwhen the lower and intermediate blocks are hoisted toward the upperblock, the intermediate block (1) being coupled to the upper block, whensaid releasing member is in the neutral position, to suspend theintermediate block from the upper block and (2) being supported by thelower block when said releasing member is in the releasing position, theintermediate block further including means for increasing the number ofrope parts when the intermediate block is suspended from the upper blockto change the transmission ratio and the permissible load of thehoisting appliance when the coupling members are engaged and theintermediate block is suspended from the upper block; and at least oneresiliently yielding stop member supported by the lower block in facingrelation to the upper block, the stop member abutting against the upperblock before the coupling members of the intermediate and upper blocksengage one another to compress said stop member, said compressed stopmember securing the lower block with respect to the upper block and,upon engagement of the coupling members, exerting a thrust tending tosecure such engagement.
 2. A change-over unit according to claim 1,characterized in that the hoisting appliance is provided with anoverload coupling, which is adapted to come into operation after thecoupling together of the coupling members.
 3. A change-over unitaccording to claim 2, wherein the overload coupling comes into operationupon continued hoisting of the intermediate and lower blocks after thecoupling together of the coupling members.
 4. A change-over unitaccording to claim 1, wherein the stop member has areas for abutmentwith the upper block that are positioned in straddling relation with theintermediate block.
 5. A change-over unit for hoisting appliancescomprising: an upper block having at least one releasable couplingmember and a plurality of rope parts; a lower block for connection to aload to be hoisted, the lower block being suspended from and hoistedtoward the upper block by the rope parts and including means forreleasing the coupling member of the upper block, said means includingat least one releasing member having a neutral position and a releasingposition; an intermediate block inserted between the upper and lowerblocks and supported by the lower block, the intermediate block havingat least one coupling member arranged to engage the releasable couplingmember on the upper block when the lower and intermediate blocks arehoisted toward the upper block, the intermediate block (1) being coupledto the upper block, when said releasing member is in the neutralposition, to suspend the intermediate block and (2) being supported bythe lower block when said releasing member is in the releasing position,the intermediate block further including means for increasing the numberof rope parts when the intermediate block is suspended from the upperblock to change the transmission ratio and the permissible load of thehoisting appliance when the coupling members are engaged and theintermediate block is suspended from the upper block; and at least oneresiliently yielding stop member supported by the upper block in facingrelation to the lower block, the stop member abutting against the lowerblock before the coupling members of the Intermediate and upper blocksengage one another to compress said stop member, said compressed stopmember securing the lower block with respect to the upper block and,upon engagement of the coupling members, exerting a thrust tending tosecure such engagement.